Portable hair dryer



y 4, 1968 w. D. TAYLOR 3,333,700

PORTABLE HAIR DRYER Filed Nov 26, 1965 5 Sheets-Sheet l INVENTOR.

BY William D. Taylor mmrmsvs y 4, 1968 w. D. TAYLOR 3,383,700

PORTABLE HAIR DRYER F'iled Nov. 26, 1965 3 Sheets-Sheet 2 INVENTOR.

Wiilicm D. Taylor BY Z W W' W p g 4% ATTORNEYS y 1968 w. D. TAYLOR3,383,700

PORTABLE HAIR DRYER Filed Nov. 26, 1965 3 SheetsSheet 3 INVENTOR.William D. Taylor I, f "i,

/ z%,, W ATTORNEYS United States Patent 3,383,700 PORTABLE HAIR DRYERWilliam D. Taylor, Wilmington, Del., assignor to Reason Corporation, acorporation of New Jersey Filed Nov. 26, 1965, Ser. No. 509,846 11Claims. (Cl. 34-99) ABSTRACT OF THE DISCLOSURE A portable hair dryerhaving an inflatable hood which is collapsible when not in use and a fanand a heater contained in a housing which is attachable directly to thehood and supported thereby.

This invention relates to portable hair dryers and more particularly itrelates to a lightweight portable axial-flow hair dryer of the typehaving a heating unit attached directly to and supported by the headwhen worn.

The portable hair dryers which have gained wide commercial acceptancehave a flexible hood, a heating unit, and a flexible hoseinterconnecting the hood and heating unit. The heating units generallyare a combined fan and heating element designed to force hot air throughthe flexible hose and into the hood. In use the heating unit is usuallyset on some supporting surface or if freedom of movement is desired, itcan usually be carried by means of a shoulder strap or the like. Thesedevices are adequate to dry hair but they are heavy to carry and thecumbersome flexible hose is a hindrance to the performance of manyactivities during a prolonged drying period. As the user of such adevice Walks, the suspended heating unit swings and repeatedly strikesthe users body. Also the suspension strap has a tendency to slip off theusers shoulder during ordinary bending movements.

Attempts have heretofore been made to eliminate the hose and strap byintegration of the hood and heating unit into one self-contained hairdryer which can be worn on the head. In general such efforts haveresulted in nothing more than dryers having attached directly to thehood conventional heating units, which are miniaturized as much aspossible. All attempts have failed to provide adequate results, becausethe heating units were too heavy or lacked the heat and air-flowcapabilities to dry hair satisfactorily within a reasonable time. Alsothe hoods for such heavy heating units, were necessarily of the hard orrigid type in order to provide sufficient supporting strength for thefan and heater. These hoods were heavy and large, occupying aninconvenient amount of space during use, storage and travel. It is anobject of this invention to provide a portable hair dryer in which anaxial-flow heating unit is attached directly to and supported by thehood, the whole apparatus being light enough to be worn on the usershead for extended periods of time without discomfort. The hood may be ofthe soft type which is collapsible and able to be folded, with aresulting package that is small enough for a womans purse. In use such ahood conforms closely to the users head, permitting a very ellicient airflow; the elimination of in convenient shoulder straps permitsunincumbered freedom of movement.

Broadly stated, the invention is an improvement in a portable hair dryerof the type having a hood for fitting about the head and covering thehair and an air inlet in the hood into which a stream of warm air isblown to dry the hair. The improvement in combination with this typehair dryer comprises a fan-heater unit having novel construction andperformance characteristics. The unit includes a tubular housing memberwith an axial bore extending through it and defining a fan section atthe inlet end of said housing member and a heating sec- 3,383,7fiPatented May 14, 1968 tion at the outlet end of said housing member.Motor means are mounted axially within said fan section and are spacedfrom the housing member to define an annular airflow channeltherebetween. A rotor is mounted for rotation by said motor and has aplurality of circumferentially-spaced impeller blades which have anairfoil profile, extending radially outwardly into the air-flow channelin the fan section. A stator having a plurality ofcircumferentially-spaced air guide vanes extending radially within theair-flow channel is mounted within the fan section for receiving the airflow from the impeller blades and guiding it into an axial-flow. Heatingmeans are mounted in said heating section and are spaced from the statorin the path of air flow for heating the air before it is blown into thehood. Means are also provided for directly connecting the outlet end ofthe housing member to the inlet of said hood and supporting the tubularmember on the hood.

The hair dryer is constructed to be lightweight and compact; for thisreason its parts are preferably constructed of lightweight plastic. Thepreferred type of construction is a vaneaxial fan which produces anaxial flow of air and consists of a housing having a cylindrical bore, arotatable wheel with radially extending blades disposed in the bore, andair guide vanes placed either before or after the wheel. A generaldescription of such a fan may be found in Kents Mechanical EngineersHandbook, Power Volume, 5th ed., New York, John Wiley & Sons, Inc., pp.l-94 or in Heating and Air Conditioning by B. H. Jennings, Scranton,Pa., International Textbook Company, 1956, pp. 434 and 443. Theconstruction of this preferred embodiment gives the added feature ofease of assembly in that the members are dimensioned to be securely heldtogether by a simple pressfit.

A preferred embodiment of the invention is described hereinbelow withreference to the drawings wherein:

FIG. 1 is a side elevation showing a portable hair dryer of theinvention as worn by a user;

FIG. 2 is an enlarged side elevation of the heating unit;

FIG. 3 is an end view of the inlet end of the heating unit;

FIG. 4 is a section taken along lines 4-4 of FIG. 2;

FIG. 5 is a section taken along lines 5-5 of FIG. 2;

FIG. 6 is a section taken along lines 6--6 of FIG. 2;

FIG. 7 is a side elevation, partly in section and partly broken away ofthe heating unit rotated about on its axis from the view shown in FIG.2; and

FIG. 8 is a schematic wiring diagram.

As shown in FIG. 1, the hair dryer is comprised of a hood 10, which isdesigned to tie around the users head about the hair to define a dryingchamber, and a heating unit 11 which is attached directly to andsupported by the hood when worn. The hood is preferably of theconventional flexible collapsible type which has a plurality of airoutlet holes 12 and a drawstring closure provided in a seam along themarginal edge defining the opening for the head.

At the back of the hood is an inlet opening 13 into which .is positionedan adaptor ring 14 as best shown in FIG. 2. The adaptor ring 14 is heldbetween inner l5 and outer 16 layers of the hood which are preferablystiffened along this portion of the hood or may have a rigidifyingmember incorporated into its construction along this portion to giveadditional support to the adaptor ring. The adaptor ring 14 has anupstanding integral cylindrical collar portion 17 which projectsoutwardly from the hood. Conventional curved slots 18 and 19 are cutinto the collar at diametrically opposite positions so that the heatingunit 11 can be attached to the hood with a simple twist connection. Theadaptor ring is preferably constructed of a lightweight rigid plasticsuch as a polyallomer, e.g.

Pro-fax 65115 (trade name of Hercules Powder Co., Wilmington, Del.) orits material equivalent.

The heating unit 11 is comprised of a housing member consisting of anelongated cylindrical tube 21 which has an axial bore 21 extendingcompletely therethrough. It is preferably formed of a lightweightplastic which has good impact strength, heat resistance, dimensionalstability, versatility of fabrication and creep resistance; one typethermoplastic which meets these requirements are the polycarbonates,e.g. Lexan 101 (trade name of General Electric Co., Chemical MaterialsDept, Pittsfield, Mass).

The tube has a discharge end 22 at which a pair of integral bayonetfasteners 23 and 24 extend radially outward at diametrically opposedportions of the tube. The outside diameter of the tube 26 at thedischarge end 22 is such that it will fit tightly into the collarportion 17. It is preferred that the inside diameter of the collarportion taper from a diameter at its outermost end of slightly largerthan the outside diameter of the discharge end 22 of the tube to adiameter at its end adjacent the ring of less than the outside diameterof the discharge end; thus upon insertion into the collar portion, thetube will be press-fit together in tight frictional engagement toprevent relative rotational movement and locked against relative axialdisplacement by the bayonet fasteners 23 and 24 twist-locked into thegrooves 18 and 19.

At the end of the tube opposite to the discharge end 22 is an inlet end25. A flange portion 26 is defined at the inlet end by the endmo-stportion of the tube flaring outwardly to an increased diameter orbell-shape.

The tube 20 tapers from its largest outside and inside diameters at theinlet end to smaller outside and inside diameters at the discharge end22. The tube 20 also has a stepped inside diameter; the wall thicknessincreases at about one-third of the axial distance into the tube fromthe inlet end and defines an annular shoulder 27 at this point and areduced inside diameter along the remaining two-thirds of the axiallength of the tube. As will become more apparent when the entireassembly has been described, a fan section 28 is defined from the inletend 25 to the shoulder 27 and a heating section 29 is defined along theremainder of the axial length of the tube from the shoulder to thedischarge end 22.

Mounted in the fan section of the tube 20 is a permanent magnetminiature DC. motor 30, which is preferred over AC. motors because itpermits the mini-mum in Weight and dimensions. Here, to reduce theweight even further, the armature of the motor is surrounded by acylindrical casing 31 which is preferably made of a lightweightthermoplastic, such as the polycarbonate de scribed. A front end motormount 32 closes the motor about the drive shaft 33 and a rear end motormount 34 closes the motor at the opposite end from which the motorterminal 35 extends. These front and rear motor mounts canadvantageously be made of a polycarbonate, such as Lexan, filled about20% with glass to increase its deflection temperature under loads. Inits position spaced concentrically within the housing, the motor definesan annular air-flow channel between the housing.

Press-fit onto the cylindrical casing 31 is a stator 36. The stator 36is comprised of a cylindrical base 37 which has an inside diameterfractionally less than the outside diameter of the casing 31 so that itcan be force-fit onto the case and held in a fixed position by therelative dimensions. Extending radially outward from the cylindricalbase 37 at circumferentially spaced intervals and extending in theair-flow channel are integral air guide vanes 38, which extend toapproximately the same diameter as the inside diameter of the tube inthe fan section immediately adjacent the shoulder 27, and upon slightradial expansion caused by forcing the stator 36 onto the motor, thediameter of the stator is expanded sufiiciently to effect a press-fitbetween at least a portion of the fan section of the tube.

The stator vanes 38 have a profile in which the leading edge 40 ischamfered and curves at an angle of about 40 relative to the major axisof the profile in a direction opposite to the direction of rotation ofthe impeller blades to be described below. The major axis extendsparallel to the tube axis because the major length 41 of the vane 38from the curved leading edge to the trailing edge is straight and ofuniform thickness.

Mounted on the motor shaft 33 is a rotor 42. The rotor has a hub 43,which includes a nose portion 44 which fits on the shaft and is heldrotatably attached to the shaft by a set-screw 45 or like means, and awheel portion 46 which extends rearwardly from the nose portion andoverlies and is radially spaced from the motor casing so that it isfreely rotatable. The nose portion 44 is inwardly bevelled from thewheel portion 46 to the leading end of the nose and is substantiallyconcentrically positioned within the inlet end of the tube so as todefine an annular converging fiow orifice 47 opening into the air-flowchannel of the fan section. Extending radially outward from the wheelportion 46 of the hub 43 and in the air-flow channel are a plurality ofintegral circumferentially-spaced impeller blades 48. The blades extendradially in the air-flow channel to a diameter slightly less than theinside diameter of the housing in the fan section. The blades have acurved airfoil profile and their nominal blade direction is at an angleto its axis of rotation which is an angle of 40 with respect to the axisof the tube 20, with the leading edge forward in the direction ofrotation. The rotor blade and the stator vanes are axially spaced fromeach other so that the air leaving the trailing edge of the rotor bladesenters the stator vanes.

Referring now to FIGS. 2, 5, 6 and 7, the heater as sembly 50 is shown.It basically consists of a frame 51, which is formed from a suitableceramic material, and a plurality of convolutions .of heater wire 52wound about and supported on the frame. The frame 5 1 is comprised offour equally spaced radially extending and axially oriented members 53which have a plurality of axially spaced grooves 54 formed on theoutermost radially extended ends of the frame members 53. Theconvolutions of heater wire are positioned within the grooves 54 and areheld in an axially spaced position. The cross-sectional thickness of theframe is preferably kept minimal and its members are arranged parallelto the tube axis so that there is no substantial interference with airflow through the heating section. Also, the heater wire is supported inthe path of air flow to provide the optimum heat transfer with the air.

The frame 5 1 is constructed to be mounted to the fan assembly by apress-fit. For this purpose axial extensions 56 and 57 are provided ontwo diametrically opposite stator blades which define generally U-shapedslots. Axial projectors 58 and 59 are provided on two frame members,which are dimensioned to be press-fit into the slots, thereby mountingthe frame in axial alignment with the fan assembly.

In assembly, the fan and heater units are fully assembled as described;then the entire assembly is axially inserted into the inlet end 25 ofthe tube 20 until the trailing edges of the stator blades 38- abutagainst the annular shoulder 27. The stator blades are press-fit intothe housing and the entire heater and fan assembly is held in the fixedposition described.

A protective outlet grill cover 60 is then inserted into the outlet endof the housing and is dimensioned to fit tightly therein by a simplepress-fit. The ribs defining the grill are spaced to permit free fiow ofair but to prevent the users hair or fingers from touching the heatingwire.

A protective inlet grill cover 62 is mounted at the inlet end 25 of thehousing. The inlet cover 62 is attached by means of screws 63 whichextend through the flange portion 26 and into circumferentially-spacedsupport portions 64 of the cover which hold the cover axially spacedfrom a major portion of the flange portion so as to leave a peripheralspace therebetween to aid in air flow into the fan section.

A damper ring 65 surrounds the periphery of the flange portion; it ismade of an elastomeric material and being positioned at the inlet end ofthe housing and along which the maximum weight of the unit isconcentrated, should the unit rest on the back of the neck of the userduring use, the damper ring will provide comfort by presenting a softcontacting surface which will also absorb most vibrations caused byrotation of the motor.

It is to be noted in FIG. 7 that there is an opening 66 through the wallof the housing into the heater section adjacent the outlet end of thetube. This opening, as shown in FIG. 1, permits the wire 67 leading tothe AC. source to be inserted into the housing and connected to theheating elements and to the motor.

As shown in FIG. 8, a 110 v. 60 cycle source is used and leads to aswitch 68. The switch connects the source to a line leading to thepermanent magnet motor 30 to the heating element 52 or both. A bridgetype full-wave rectifier 69 is provided at the motor 30 to rectify thealternating current to direct current and a voltage dropping resistor 70is connected in series with the rectifier to reduce the voltage appliedthereto. An alterntaive means of providing reduced voltage is to deleteresistor 7i and use instead the voltage drop across the heating coil.Athermostat 71 can be connected in series with the heating element whichin this case is a 300 W. resistance coil heater, to control the airtemperature of the dryer. As shown in FIG. 2, a portion of one framemember has been removed to leave a space 72 in which the thermostat canbe mounted. A thermostat set to operate in a range of 60 to 195 F. wouldbe satisfactory.

It is preferred to construct the rotor, stator, inlet and outlet covers,and tube housing of a thermoplastic, such as the polycarbonate specifiedbecause of the properties described. The advantages of a lightweight butstrong material are very important in the application. In fact theentire weight of the heating unit in the embodiment shown is only 6 /2ounces. Furthermore the structural arrangement provides the maximum inequipment in the minimum amount of space; in the embodiment described,for example, the overall length of the heating unit is less than 5inches and the diameter of the housing is less than 2 inches.

In spite of the miniature size which the construction of the inventionpermits, it nevertheless provides a very satisfactory hair dryer. Thearrangement .of rotor vanes and stator blades is designed to givemaximum axial airflow. The rotor 42, which rotates clockwise in theembodiment shown, in cooperation with the convergent annular floworifice accelerates the air-flow into the housing and the stator 38increases the static pressure as it is difiused and delivered axially.The outlet velocity from the stator is axial. It is interesting to notethat the entire fan section occupies only about one-third of the lengthof the tubing, and the arrangement described is so efiicient that itachieves a static efficiency of 85%.

As the air flows into the heating section, it flows over the heatingelements 52, which extend between the frame members in the direct pathof the axial airflow, and the cross section of the frame is minimal sothat there is no substantial interference with air-flow as it passesthrough the heating section.

I claim:

1. In a portable hair dryer of the type having a flexible hood forfitting about the head and covering the hair, the hood being inflatableto have a crown portion and lower portions, and having an inlet forreceiving a stream of warm air to dry the hair, and being collapsiblewhen not in use, the improvement in combination therewith comprising:

(a) a tubular housing member having an axial bore extending therethroughand defining therein a fan section at an inlet end of said housingmember and a heating section at the outlet end of said housing member,

(b) an electric motor mounted axially within said fan section andannularly spaced in said housing member to define an annular air-flowchannel therebetween,

(c) a fan including a rotor having a plurality ofcircumferentially-spaced impeller blades therein mounted for rotation bysaid motor, said blades extending radially outward into the air-flowchannel in the fan section,

(d) electric heating means mounted in said heating section of thetubular housing and spaced from said rotor in the path of air flow forheating the air before it is blown into the hood, and

(e) means for directly connecting the outlet end of the housing memberto the inlet of said hood, the housing member being suspended from alower portion of the hood and supported thereby.

2. In a portable hair dryer of the type having a flexible hood forfitting about the head and covering the hair, the hood being inflatableto have a crown portion and lower portions, and having an inlet forreceiving a stream of warm air to dry the hair, and being collapsiblewhen not in use, the improvement in combination therewith comprising:

(a) a tubular housing member having an axial bore extending therethroughand defining therein a fan section at an inlet end of said housingmember and a heating section at the outlet end of said housing member,

(b) a direct current electric motor mounted axially within said fansection and annularly spaced in said housing member to define an annularair-flow channel therebetween,

(-c) a fan including a rotor having a plurality ofcircumferentially-spaced impeller blades therein mounted for rotation bysaid motor, said blades extending radially outward into the ar-flowchannel in the fan section,

((1) electric heating means mounted in said heating section of thetubular housing and spaced from said rotor in the path of air flow forheating the air before it is blown into the hood, and

(e) means for directly connecting the outlet end of the housing memberto the inlet of said hood, the housing member being suspended from alower portion of the hood and supported thereby.

3. A portable hair dryer according to claim 2 wherein said motor is apermanent magnet direct current motor and circuitry is provided forfeeding an alternating current to said heating means and rectifying saidalternating current to direct current for said motor.

t. A portable hair dryer according to claim 1 wherein said fan includesa stator having a plurality of circumferentially spaced air guide vanesextending radially within the bore of the fan section.

5. A portable hair dryer according to claim 1 wherein said stator guidevanes have a curved profile for receiving the air flow from the impellerand guiding into into an axial flow.

d. A portable hair dryer according to claim 5 wherein said statorfurther comprises a cylindrical base part havmg a bore corresponding tothe outside diameter of the motor for attachment thereon, and said airguide vanes extend radially outward from said cylindrical part, theiroutside diameter corresponding to the bore of said hous mg forattachment therein, whereby said stator (a) is fixedly positioned withinsaid housing and (b) its bore part supports said motor.

7. A portable hair dryer according to claim 1 wherein said rotorimpeller blades have an airfoil profile.

8. A portable hair dryer according to claim 1 wherein said fan is avaneaxial fan.

9. A portable hair dryer according to claim 5 wherein said impellerblades are inclined at an angle to the rotors axis of rotation with theleading edge of each blade forward in the direction of rotation and saidstator vanes have a profile with the leading edge thereof curvedrelative to the major axis of the profile in a direction opposite to thedirection of rotation of the impeller blades and the major length of theprofile extended parallel to the tube axis to receive the air from theimpeller blades and guide it into an axial flow.

10. A portable hair dryer according to claim 1, wherein said inlet endof said housing includes an outwardly flared flange portion whichdefines an annular converging orifice, and said rotor has a central,bevelled nose portion adjacent said inlet end.

11. In a portable hair dryer of the type having a flexible hood to fitabout the head and cover the hair, said hood being inflatable to have acrown portion and lower portions, and having an air inlet for receivinga stream of warm air to dry the hair, and being collapsible when not inuse, the improvement in combination therewith comprising:

(a) a tubular housing member made of light weight plastic having anaxial bore extending therethrough and defining therein a fan sectionalong a first axial length at an inlet end of the housing member and aheating section along a second :major axial length at the outlet end ofsaid housing member, an outwardly flaring flange portion at the inletend of the housing,

(b) a permanent magnet DC. motor extending axially within said fansection and annularly spaced from said housing member to define anair-flow channel therebetween,

(c) a rotor made of lightweight plastic mounted for rotation by saidmotor, said rotor having a bevelled nose portion positioned within theinlet end of said housing and defining an annular converging orifice, awheel portion extending rearwardly from said nose portion and overlyingand radially spaced from said motor, and a plurality of integralcircumferentiallyspaced impeller blades which extend radially in theair-flow channel to a diameter slightly less than the inside diameter ofthe housing member in the fan section, said blades having an airfoilprofile and inclined at an angle to its axis of rotation with theleading edge forward in the direction of rotation,

(d) a stator made of lightweight plastic having a cylindrical basemember, which is press-fit on said motor, and a plurality of integralcircumferentiallyspaced air guide vanes extending radially within theair-flow channel and in press-fit engagement with said housing member inthe fan section to hold said stator in a fixed position and to supportsaid motor therein, said vanes having a profile with the leading edgecurved relative to the major axis of the profile in a direction oppositeto the direction of rotation of the impeller blades and the major lengthof the profile extended parallel to the tube axis to receive the air andguide it into an axial flow,

(e) an electric heater assembly mounted on said stator and extendingaxially in said heating section, said assembly having a frame formed ofelongated members circumferentially spaced and defining a cross sectionof narrow radially extending members, and a heater element wound aboutthe elongated edges of the frame and supported in alignment with theairflow channel in the path of the axial air-flow to heat the air,

(if) means for directly connecting the outlet end of the housing memberto the inlet end of the hood and supporting the tubular member bysuspending it from a lower portion of the hood,

(g) protective grills made of lightweight plastic mounted on thei nletand outlet ends of said housing member, and

(h) circuitry for feeding an alternating current source to said heaterelement and rectifying said alternating current to direct current forsaid motor.

References Cited UNITED STATES PATENTS 2,465,446 3/1949 Gorfin et al310-154 X 2,472,873 6/ 1949 Woodrum 3499 2,478,559 8/1949 Bergeron34-243 X 2,820,305 1/1958 Brown 34-99 3,023,515 3/1962 Stern 34-993,047,753 7/1962 Westell 230-117 X 3,168,382 2/1965 Chambers et al.34-99 3,261,107 7/ 1966 Ponczek et al 3499 OTHER REFERENCES Electronicand Radio Engineering, McGraw-Hill Book Co. Inc., 1955, pp. 706 and 707.

FREDERICK L. MATTESON, JR., Primary Examiner. A. D. HERRMANN, AssistantExaminer.

